The physical map ofMus musculus chromosome 11 reveals evolutionary relationship with different syntenic groups of genes inHomo sapiens

Summary The physical localization of sequences homologous to three cloned genes was determined by in situ hybridization to metaphase chromosomes. Previous work had assigned the skeletal myosin heavy chain gene cluster (Myh), the functional locus for the cellular tumor antigen p53 (Trp53-1), and the cellular homologue of the viral erb-B oncogene (Erbb) toMus musculus chromosome 11 (MMU11). Our results provide regional assignments ofMyh andTrp53-1 to chromosome bands B2C, and ofErbb to bands A1A4. Taken together with in situ mapping of three other loci on MMU 11 (Hox-2 homeobox-containing gene cluster, theSparc protein, and theColla-1 collagen gene), which have been reported elsewhere, these data allowed us to construct a physical map of MMU11 and to compare it with the linkage map of this chromosome. The map positions of the homologous genes on human chromosomes suggest evolutionary relationships of distinct regions of MMU11 with six different human chromosome arms: 1p, 5q, 7p, 16p, 17p, and 17q. The delineation of conserved chromosome regions has important implications for the understanding of karyotype evolution in mammalian species and for the development of animal models of human genetic diseases.     

Lectin histochemical study on the infraorbital gland of the Japanese serow (Capricornis crispus)

Histology and lectin histochemistry were performed in the infraorbital gland of the Japanese serow. The gland is composed of glandular tissues and a pouch filled with the secretion. The tissues consist of an inner layer of sebaceous glands and an outer layer of apocrine glands. The male sebaceous layer is made up of the ordinary type, whereas the female's layer consists of the ordinary and modified types. In the apocrine gland stained with Arachis hypogaea (PNA), nine different patterns of glandular tubules were distinguished on the basis of staining of the cytoplasm, the Golgi area of secretory cells and secretion. Secretory modes of apocrine secretion and exocytosis were included in these stainings. Myoepithelial cells stained constantly with Glycine max (SBA) except when only the Golgi area of secretory cells was positive. The modified sebaceous gland was stained with PNA, SBA, Ricinus communis I (RCA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A) and Ulex europaeus I (UEA), while the ordinary type was positive in PNA, RCA, SBA, WGA and Con A. The secretion in the pouch was stained with PNA, RCA, SBA, Dolichos biflorus (DBA), WGA and Con A. These findings suggest that the modified sebaceous gland contains large amounts of glycoconjugates and the apocrine gland shows a cyclic secretory process of apocrine secretion and exocytosis.     

Complex segregation analysis of plasma lipid and lipoprotein variables in a Jerusalem sample of nuclear families

Plasma lipid and lipoprotein concentrations from 3,074 nuclear families in the multiethnic Jerusalem Lipid Research Clinic study population were analyzed for possible involvement of major genes in determination of high levels of these traits. Complex segregation analysis under a mixed model including major gene and multifactorial transmissible components was performed on transformed-plasma lipids and lipoproteins after covariance adjustment for age, sex and environmental measures. Likelihood analysis provided evidence for recessive major genes influencing plasma triglyceride, and low-density lipoprotein cholesterol (LDL-C). The estimated gene frequencies for triglyceride and for hyperbetalipoproteinemia in our study population were about 0.1. Our positive results for total cholesterol and high-density lipoprotein cholesterol (HDL-C) were nonconclusive and the major effects could result from causes other than major genes. The mixed-model parameters were homogeneous across origin groups for LDL-C and HDL-C and heterogeneous for total plasma cholesterol and triglyceride. The multifactorial-transmission heritability index was similar in all origin groups for all the traits. The origin heterogeneity in the major gene parameters appeared to be mainly due to the North African group which favored a multifactorial transmission for all traits except for LDL-C.     

The presence of endometrial cells in cervical smears in relation to the day of the menstrual cycle and the method of contraception

The presence of endometrial cells in cervical smears was studied in a large series of women participating in a population screening program for cervical cancer, in relation to different time periods of the menstrual cycle and to the method of contraception practiced. In the total group of women studied, endometrial cells were present in an average of 12% of the cervical smears. In women who were menstruating cyclically, the percentage of cervical smears containing endometrial cells was not age dependent. Only in women over 52 years was a lower number of endometrium-positive cervical smears found: in postmenopausal women, 0.6% of smears were found to contain endometrial cells. In menstruating women, the frequency of endometrial cells in cervical smears was highest during the menses. After day four, through the proliferative phase, the percentages of cervical smears containing endometrial cells markedly decreased. During the secretory phase, an average of 2% of the smears contained endometrial cells; in the premenstrual phase (after day 25), the percentages of endometrial cell-positive smears rose again. When related to the method of contraception practiced, significant differences in the percentages of cervical smears with endometrial cells appeared. In women using oral hormonal contraceptives, the average numbers of smears containing endometrial cells for the whole cycle as well as for each period of the cycle were significantly lower. This phenomenon might be due to endometrial atrophy on the basis of prolonged use of oral hormonal contraceptives. In women wearing an intrauterine device, at any moment the frequencies of smears with endometrial cells present were significantly higher than the values found in women using any other method of contraception or not using contraceptives. The evaluation of cells originating from the endometrium requires considerable experience. The identification of endometrial cells can be made with greater confidence when the cytologist is aware of the exact date of the menstrual cycle and of the impact on the presence of endometrial cells in cervical smears caused by different methods of contraception.     

Histochemical and ultrastructural data on the adrenergic and cholinergic innervation of the epididymis in the mouse

The adrenergic and cholinergic innervation of the epididymal duct in the mouse has been investigated using histochemical methods and electron microscopy. This study demonstrates that the epididymal innervation of the mouse does not really differ from that of other mammals. Cholinergic nerves are mainly vascular, even in the cauda where cholinesterase activity is increased within the tubular musculature. Catecholamine fibres ensure the motricity of the wall of the canalicular system, particularly the terminal segment where the smooth muscle fibres are specifically differentiated.     

Development of the bovine ileal mucosa

The development of the bovine ileal mucosa was studied with particular reference to maturation during the fetal and neonatal period. In this region, by 4-5 months of fetal development, vacuolation of the epithelial cells had occurred on the villi, and the goblet and absorptive cells in the crypts were present. By 6-9 months, the villi were longer and more numerous than in the previous stages. At the same time, the vacuolated cells could be seen predominantly on the upper half of each villus. The absorptive cells and goblet cells were more distinct in the crypt and lower half of each villus. Moreover, the goblet cells showed differences in mucin, while in the submucosa the lymphoid follicles were seen to have enlarged to become a prominent feature of the Peyer's patches at this stage. At birth, in suckled animals, the ileal cells on the lower area of each villus and in the crypt appeared more like mature cells. In contrast, there were numerous inclusion bodies in epithelial cells on the upper half of each villus. They appeared in the apical portion of the cytoplasm as vacuoles with stainable or dense contents. By 1 week, however, epithelial cells no longer contained inclusion bodies, and absorptive and goblet cell populations had begun to emerge from the crypts. These histological results suggest that the bovine ileal mucosa has two distinct turning points during its development in the fetus and the neonate. Initially all the mucosal structures are present in fetuses at 6-7 months of gestation, and then the vacuolated cells covering the ileal villi are replaced by mature, nonpinocytosing epithelium which emerges from the crypts on or before the 7th day after birth (ileal closure).     

Ultrastructure of cementum formation on partially formed teeth in dogs

Cementum crystals and matrix vesicles on the root surface of partially formed teeth in dogs were examined with a transmission electron microscope. Fine filamentous crystals were observed in the cementum calcifying fronts. The running pattern was mainly parallel to the root surface in the apical region and perpendicular to the root surface in lateral and coronal regions. Matrix vesicles were observed at the apical half of the periodontium, but not observed at the coronal region. These findings suggest that the parallel-arranged cementum would become the light-microscopic lamellar type and the perpendicular one the light-microscopic dense-line structure when fully developed. Moreover, cementum formation occurs due to two kinds of mechanisms: participation of matrix vesicles and secondary calcification (= additional cementogenesis).     

Genetic mechanisms of tumor-specific loss of 11p DNA sequences in Wilms tumor.

Wilms tumor, a common childhood renal tumor, occurs in both a heritable and a nonheritable form. The heritable form may occasionally be attributed to a chromosome deletion at 11p13, and tumors from patients with normal constitutional chromosomes often show deletion or rearrangement of 11p13. It has been suggested that a germinal or somatic mutation may occur on one chromosome 11 and predispose to Wilms tumor and that a subsequent somatic genetic event on the normal homologue at 11p13 may permit tumor development. To study the frequency and mechanism of such tumor-specific genetic events, we have examined the karyotype and chromosome 11 genotype of normal and tumor tissues from 13 childhood renal tumor patients with different histologic tumor types and associated clinical conditions. Tumors of eight of the 12 Wilms tumor patients, including all viable tumors examined directly, show molecular evidence of loss of 11p DNA sequences by somatic recombination (four cases), chromosome loss (two cases), and recombination (two cases) or chromosome loss and duplication. One malignant rhabdoid tumor in a patient heterozygous for multiple 11p markers did not show any tumor-specific 11p alteration. These findings confirm the critical role of 11p sequences in Wilms tumor development and reveal that mitotic recombination may be the most frequent mechanism by which tumors develop.     

Structure-activity relationship of gramicidin S analogues on membrane permeability

The previous study of the action of gramicidin S on bacteria (Katsu, T., Kobayashi, H. and Fujita, Y. (1986) Biochim. Biophys. Acta 860, 608-619) prompted us to investigate further the structure-activity relationship of the gramicidin S analogues on membrane permeability. Two types of the gramicidin S analogues were used in the present study: (1) cyclo(-X-D-Leu-D-Lys-D-Leu-L-Pro-)2, where X = Gly, D-Leu and D-cyclohexylalanine (D-cHxAla); (2) N,N'-diacetyl derivative of gramicidin S (diacetyl-gramicidin S) which lacks a cationic moiety of gramicidin S. All the analogues have a beta-sheet conformation as gramicidin S. The following cellular systems were used: Staphylococcus aureus as Gram-positive bacteria, Escherichia coli as Gram-negative bacteria, human erythrocytes, rat liver mitochondria and artificial liposomal membranes. It was found that gramicidin S and one of the type 1 analogues having X = D-cHxAla induced the efflux of K+ through the cytoplasmic membrane of all types of the cells. In addition, these two peptides had the ability to lower the phase transition temperature of dipalmitoylphosphatidylcholine. Accordingly, it was concluded that, if peptides can expand greatly the membrane structure of neutral lipids which constitute main parts of the biological membrane, they can stimulate the permeability of cells without any selectivity. The action of the type 2 peptide, diacetyl-gramicidin S, was strongly cell dependent. Although this peptide stimulated the efflux of K+ from mitochondria, it did not do so efficiently, if at all, from S. aureus, E. coli and erythrocytes. In experiments using liposomes, diacetyl-gramicidin S increased markedly the permeability of liposomes composed of egg phosphatidylcholine. The presence of egg phosphatidylethanolamine or cholesterol reduced its activity. These results on liposomes explained well the low sensitivity of diacetyl-gramicidin S against E. coli and erythrocytes in terms of lipid constituents of the membranes. The mechanism of action of diacetyl-gramicidin S was discussed from the formation of a boundary lipid induced by this peptide.